• 한국생물공학회:학술대회논문집
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• 2003.04a
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• pp.611-614
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• 2003

The rheological properties of exopolysaccharide, p-KG03, produced by marine microalgae Gyrodinium impudicum strain KG03 had been studied. The intrinsic viscosity of this p-KG03 was calculated to 65.22 and 50.75 $d{\ell}/g$ using Huggins and Kramer equations (xanthan gum 24.41 and 24.03). Aqueous dispersions at p-KG03 concentrations ranging from 0.1 to 1.0 % (w/w) showed marked shear-thinning properties as Power-Law behavior. In aqueous dispersions of p-KG03 1.0 %, consistency index (K) and flow behavior index (n) were 2,172 and 0.52. The apparent viscosity and the influence of shear rate on different conditions as p-KG03 concentrations, pH, NaCl, $CaCl_2$ and temperature in aqueous solutions were measured. And p-KG03 had mixed with aqueous solutions of xanthan gum and gellan gum, and invested the change of mixed aqueous solution behavior.

• Preventive Nutrition and Food Science
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• v.9 no.3
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• pp.206-212
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• 2004

Prickly pear extract (PPE) was fermented by Lactobacillus rhamnosus LS at 3$0^{\circ}C$ for 2 days. To improve the physicochemical properties of fermented PPE, it was fortified with food polysaccharides (0.2 %) or seaweed calcium before lactic acid fermentation. The viable cell counts, flow behavior, titratable acidity and color stability of fermented PPE were evaluated during 4 weeks of cold storage. Addition of xanthan gum or glucomannan increased the apparent viscosity and acid production, viable cell counts and red color of PPE were also well maintained during the cold storage. However, fermenting PPE with gellan gum resulted in a decrease in relative absorbance, indicating lower color stability. In particular, PPE fortified with carrageenan or alginic acid showed reduced acid production and lower viable cell counts. Addition of seaweed calcium at a 0.1 % level had positive effects on color stability, and helped maintain viable cell counts of 4.1 ${\times}$ 10$^{9}$ CFU/mL. This study demonstrated that xanthan gum could be used as a good thickening agent and stabilizer for retaining viable cell counts and red color during the cold storage in PPE fermented by lactic acid bacteria.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.27 no.2
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• pp.101-107
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• 2021

Time-temperature integrators (TTIs) based on aqueous enzyme solutions produce transparent colors which lead to difficulty in distinguishing its color change by naked eye. In this present study, this issue has been solved by increasing the opacity of laccase-based TTI without changes in the kinetics (same zero-order reaction) and temperature dependency (similar Arrhenius activation energy values) of the color change. The opacity was increased by introducing TiO₂, latex, BaSO₄, or ZnO, in combination with a hydrocolloid (xanthan gum, acacia gum, pectin, and CMC) into the TTI system. The combination of TiO₂ and xanthan gum was the best. This finding broadened the advantages of laccase-based TTI to more practical uses for consumer convenience.

• The Korean Journal of Pesticide Science
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• v.10 no.1
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• pp.28-35
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• 2006

This study was conducted to optimize formulation factors of a self-dispersible floating granule of flucetoaulfuron that can be used at a low application volume (5 kg $ha^{-1}$). SPA and xanthan gum were selected as a binder because blending of them showed good granulation and floatation. Potassium chloride selected as a filler also showed good granulation, floatation and disintegration properties. Among wetters and dispersants, Surfynol 440 gave the best dispersibility The optimum granule size was determined to be 1.0 mm considering floating time and dispersibility. Flucetosulfuron was mixed with the blend of SPA and xanthan gum, potassium chloride, and Surfynol 440 and formulated as a floating self-dispersible granule at 1.0 mm in diameter. Indoor and outdoor field experiments showed that the floating granule of flucetosulfuron performed well, covering long range from the application spot up to 15 m in weed control. Therefore, this floating technology may be used for laborsaving herbicide formulation development and help to reduce workloads for herbicide application.

• Current Research on Agriculture and Life Sciences
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• v.29
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• pp.55-62
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• 2011

In this study, four natural polymers were added into rice flour to prepare rice noodle and their effects on the fabrication of rice noodle were examined. Also, the effect of water dosage and natural polymer content on the noodle-making properties of rice noodle was investigated. Addition of xanthan gum showed the best performance of noodle formation, while crystalline cellulose did not help the improvement of noodle making properties of rice dough. Regardless of natural polymer type, the amount of water dosage and polymer content influenced significantly the performance of rice noodle formation. In case of xanthan gum, 3% polymer content and 64~68% water dosage were the best conditions to fabricate a good rice noodle. Guar gum showed the best performance at 2~3% guar gum addition and 66% water content. Finally, 3% carboxymethyl cellulose and 64% water dosage were optimum condition for good formation of rice noodle.

• Korean Journal of Food Science and Technology
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• v.13 no.1
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• pp.6-14
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• 1981

In an attempt to make dried noodles with composite flours utilizing rice and wheat flours, noodle-making characteristics were improved by the addition of popped rice and wheat flours to rice flour. Their quality was studied in terms of physical properties, noodle-making characteristics, cooking quality test and sensory evaluation. Dried noodle of the composite flour was produced by the conventional method. The results are summerized as follows; 1. In comparing the composite flours, the rice flour containing 30% popped rice flour had a lower maximum viscosity than that with 40% popped rice flour by method of amylograph. The composite flour(20% rice+30% popped rice+50% wheat flour) with added 2% xanthan gum showed the viscosity characteristics which was similar to that of wheat flour. 2. Addition of $1.5{\sim}2.0%$ xanthan gum and $40{\sim}50%$ wheat flour to rice and popped rice flour mixture helped to improve the noodle making properties and the cooking quality, and the noodle making properties and the cooking quality of the mixed flour were almost the same as those of wheat flour alone. 3. The composite flour (rice+popped rice+wheat flour) with xanthan gum showed a higher score in sensory evaluation than that without xanthan gum. The general acceptability scores obtained with the noodle products made of the composite flours with 30% popped rice flour was not significantly different from that of noodle products made of wheat flour alone. However, the noodle products made of the composite flours showed rather higher scores in odor and palatability than the products made of wheat flour alone.

• Journal of the Korean Society of Food Science and Nutrition
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• v.32 no.1
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• pp.82-88
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• 2003

Four kinds of low calorie mayonnaises containing 1.2% of sodium alginate, 1.0% of guar gum, 1.0% and 1.2% of xanthan gum and one control mayonnaise containing 78.5% of oil without gums were manufactured in pilot scale. Fresh control mayonnaise was higher in viscosity and turbidity than low calorie mayonnaise with gums. During storage at -1$0^{\circ}C$, viscosity and turbidity of control mayonnaise decreased sharply, whereas those of low calorie mayonnaise with gums decreased slightly. Scanning electron microscopy showed that fresh mayonnaise was composed of heterogeneous population of dispersed spherical oil droplets (<10 ${\mu}{\textrm}{m}$), and oil droplet size of control mayonnaise was smaller than any other low calorie mayonnaise. During storage at -1$0^{\circ}C$, a shift in oil droplet size toward larger oil droplets was frequently observed in control mayonnaise as a result of coalescence of oil droplets. Oil separation and turbidimetric study also confirmed that coalescence of oil droplets was occurring during this accelerated aging treatments.

• Geomechanics and Engineering
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• v.33 no.2
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• pp.221-230
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• 2023

The liquefaction of soil occurs when a soil loses strength and stiffness because of applied stress, such as an earthquake or other changes in stress conditions that result in a loss of cohesion. Hence, a method for improving the strength of liquefiable soil needs to be developed. Many techniques have been presented for their possible applications to mitigate liquefiable soil. Recently, alternative methods using biopolymers (such as xanthan gum, guar gum, and gellan gum), nontraditional additives, have been introduced to stabilize fine-grained soils. However, no studies have been done on the use of carrageenan as a biopolymer for soil improvement. Due to of its rheological and chemical structure, carrageenan may have the potential for use as a biopolymer for soil improvement. This research aims to investigate the effect of adding carrageenan on the soil strength of treated liquefiable soil. The biopolymers used for comparison are carrageenan (as a novel biopolymer), xanthan gum, and guar gum. Then, sand samples were made in cylindrical molds (5 cm × 10 cm) by the dry mixing method. The amount of each biopolymer was 1%, 3%, and 5% of the total sample volume with a moisture content of 20%, and the samples were cured for seven days. In terms of observing the effect of temperature on the carrageenan-treated soil, several samples were prepared with dry sand that was heated in an oven at various temperatures (i.e., 20℃ to 75℃) before mixing. The samples were tested with the direct shear test, UCS test, and SEM test. It can increase the cohesion value of liquefiable soil by 22% to 60% compared to untreated soil. It also made the characteristics of the liquefiable increase by 60% to 92% from very loose sandy soil (i.e., ϕ=29°) to very dense sandy soil. Carrageenan was also shown to have a significant effect on the compressive strength and to exceed the liquefaction limit. Based on the results, carrageenan was found to have the potential for use as an alternative biopolymer.

• Korean Journal of Food Science and Technology
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• v.41 no.6
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• pp.668-672
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• 2009

Cookies containing wheat flour mixed with 10, 30 or 50% esterified with octenylsuccinic anhydride (OSA, 3%) and dry-heated ($130^{\circ}C$, 2 hr) high amylose rice (Goami 2) starch (DH-OSAR) were prepared and then their physical and digestive properties were evaluated. When the amount of added DH-OSAR increased, the hardness and brittleness of the cookies decreased, and L (brightness) value increased. For the digestive properties, the cookies containing 50% DH-OSAR significantly increased the amount of slowly digestible starch (SDS), and decreased the amount of rapidly digestible starch (RDS), resulting in the lowest expected Glycemic Index (eGI) among tested cookies. Although the cookies containing DHOSAR were inferior to the control, the addition of xanthan gum (0.5% based on total powder amount) significantly improved their textural and sensory properties. Specially, the cookies containing 50% DH-OSAR and the addition of 0.5% xanthan gum showed the lowest eGI value, maintaining the improved textural and sensory properties.

• Food Science and Biotechnology
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• v.17 no.1
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• pp.20-25
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• 2008

Effects of commercial and lab-generated gellan gums on the textural properties, structure, and aging of wheat and maize starch gels were investigated using a rapid visco-analyzer (RVA), rheometer, scanning electron microscope (SEM), and X-ray diffractometer. Gellan and guar gums increased the peak and final viscosities, but xanthan gum and gum arabic reduced them. The maize starch had higher breakdown viscosity than the wheat starch, regardless of the type of gum. The hardness of all starch gels increased during storage, but their cohesiveness and springiness decreased. The degree of the gel hardness showed higher in maize starch than in wheat starch and the effect of gum addition had a difference with gum type. The wheat starch-guar and -gellan gum mixed gels showed higher elasticity and cohesiveness after storage. The starch-gellan gum mixed gels had dense and stable network structures, and were well maintained even after 7 days of storage. Most of the gums had anti-aging effect on X-ray diffraction pattern of starch gels.